80 JOURNAL OF COSMETIC SCIENCE , -: o a Fiber identification " :: C) 22 I ..... • .... :'[ 22 •"'1 • • • •beTidenti,•atiø b Figure ]•. (a) C•eep obse•ed in unt•eatcd/unake•ed hai• •be•s as a •unction o• ex•su•e ti•e to constant tension unde• 40 g o• •ei•ht. (b) C•eep obse•ed the •oJy•e•ic PQ-]O as a •unction o• ex•su•e ti•e to constant tension unde• 40 • o• •eight. (c) C•eep obse•cd in unaltered haJ• fibers exposed exposure ti•e to constant tension unde•

CATIONIC CONDITIONING COMPOUNDS 81 88- 66- 88 44 22 0 T,rne Under Constant L•ad (h i i i ! ie tl ii • I I plC ø Figure 14. Continued. as "in-depth" studies were carried out, yielding similar and reproducible results. A typical example of the effects of cationic treatments on improving creep resistance is givrn hrrr Creep studies were carried out under the same environmental conditions used for the scale-lifting studies. Untreated hair fibers and hair fibers exposed to one and ten appli- cations of cationics were individually mounted and freely suspended under a constant tension of 40 g. Their creep (extension) was measured as a function of time up to 96 hours. Figure 14a shows creep measured in fine, medium, and coarse untreated/unaltered hair fibers (controls). The coarse hair fibers were not affected by the constant tension of 40 g within the time span of 96 hours, and measurable creep was not observed. However, hair fibers of medium and fine diameters did show increasing creep with time. Some of the fine hair fibers failed shortly after application of tension. Figure 14b shows creep measured in hair fibers exposed to one application of the polymeric PQ-10. As observed for the control, the coarse hair fibers showed no creep with a constant tension of 40 g within 96 hours, while hair fibers of medium and fine diameters showed increasing creep under tension as a function of exposure time. The levels of creep were generally lower than those observed for the controls. One of the fine hair fibers failed shortly after application of tension. Creep measured in unaltered hair fibers, which had been exposed to ten applications of PQ-10, is shown in Figure 14c. Surprisingly, the medium-diameter hair fibers displayed